Gian Piero Gasperini was denied any joy on his return to Inter Milan as Santiago Garcia's own goal gifted the Nerazzurri an undeserved victory.
Palermo's current coach was unceremoniously sacked as Inter boss having overseen just five games last season, but his revenge mission came undone when Rosanero full-back Garcia contrived to put through his own net in the 74th minute.
Inter appeared lost without suspended striker Antonio Cassano and influential midfielder Wesley Sneijder, currently a peripheral figure at the San Siro due to a contract dispute.
Whether unmerited or not, a first win in four outings boosts the Nerazzurri back into third place, while Palermo slip back into 17th and within two points of the relegation places.
Garcia had to look lively to cut out Philippe Coutinho's early drive but Palermo would have a relatively comfortable opening 45 minutes.
A soft and slow Inter midfield offered precious little creative spark and it was not until the 32nd minute that Esteban Cambiasso drew a fine parry from Samir Ujkani with a fierce shot on the volley.
At the other end, Samir Handanovic dithered unnecessarily with Edgar Barreto on the prowl and Diego Milito's cross-cum-shot did little to trouble Ujkani, instead shaving the outside of a post.
The hosts were limping towards half-time but Rodrigo Palacio offered a rare flash of inspiration with his lung-busting dribble through Palermo's defence, but there was no-one ready to convert the cross.
There was no tactical switch from Inter coach Andrea Stramaccioni at the break and Palacio was soon found staggering around the ball instead of slotting it home from close range.
A frustrated Andrea Ranocchia stepped up from defence to try and make a difference but his shot flew high and wide. Stramaccioni took the hint and threw on Fredy Guarin for Milito, with Yuto Nagatomo replacing Javier Zanetti.
Guarin made an instant impact, catching Ujkani off-guard with a looping effort that the Albanian keeper struggled to catch.
Inter had shown faint signs of initiative but, when the breakthrough came in the 74th minute, it was premature and rather unfair on Palermo.
With the Palermo defender under no pressure, an innocuous cross from Ranocchia took a cruel deflection off Garcia and left Gasperini open-mouthed on the touchline.
There was time for Stramaccioni to hand McDonald Mariga his first league appearance of the season but the Kenyan could not fashion a second goal as Inter held on.